Why SPA and Angular 2?

An SPA renders only one HTML page from the server, when the user starts the app. Along with that one HTML page, the server sends an application engine to the client. The engine controls the entire application including processing, input, output, painting, and loading of the HTML pages. Typically, 90–95 percent of the application code runs in the browser; the rest works in the server when the user needs new data or must perform secured operations such as authentication. Because dependency on the server is mostly removed, an SPA autoscales in the Angular 2 environment: No matter how many users access the server simultaneously, 90–95 percent of the time the app's performance is never impacted.

Also, because most of the load is running on the client, the server is idle most of the time. Low demand on server resources reduces stress on the server significantly, potentially reducing server costs.

Another advantage of Angular 2 is that it helps SPAs to consume microservices effectively.